5 Things You Should Know Before the Stock Market Opens

NEW YORK ( TheStreet) -- U.S. stock futures were slipping Friday suggesting a weaker Wall Street open as China's growth slowed and a rocket launch in North Korea failed.

European shares posted declines, while Asian shares finished with gains, taking in stride data that showed China's gross domestic product in the first quarter rose 8.1%, the lowest since the first quarter of 2009. Economists forecast GDP growth of 8.3%.

Asian markets also were buoyed by news that a multistage stage rocket launched by North Korea Friday morning exploded less than two minutes after takeoff.

The economic calendar in the U.S. Friday includes the consumer price index for March at 8:30 a.m. EDT and the University of Michigan's gauge of consumer sentiment for April at 9:55 a.m.

Economists expect a CPI increase of 0.3%, down from 0.4% the previous month. The core number, which excludes food and energy, is expected to rise 0.2% from 0.1% in February.

The consumer sentiment estimate is forecast to decline slightly to 76.1 from 76.2 in March.

Google reported first-quarter earnings of $10.08 a share on revenue of $8.14 billion, excluding traffic acquisition costs. Total revenue came in at $10.65 billion. Revenue in the U.S. rose 22% year over year to $4.9 billion, while revenue outside the U.S. jumped 26% to $5.8 billion.

Google also said it would be creating a new class of stock, effectively issuing a stock split that is "designed to preserve the corporate structure that has allowed Google to remain focused on the long term." The new class of stock won't have any voting power and will help Google's senior leaders retain control years from now.

Analysts expect JPMorgan to post first-quarter earnings of $1.18 a share on revenue of $24.68 billion, while Wells Fargo is seen posting profit of 73 cents a share in the March-ended period on revenue of $20.46 billion.

Apple ( AAPL) called allegations from the U.S. Department of Justice that it colluded with publishers over e-book pricing "simply not true."

Coinstar said it sees core earnings from continuing operations of $1.36 to $1.40 a share on revenue of $567 million to $569.2 million for the three months ended March 31. Analysts are calling for profit of 90 cents a share on revenue of $537.7 million.

Coinstar attributed the forecast, in part, to strong DVD demand from consumers in February and March.